I think I would have been more worried about the scope than the mount. How did the scope fair? I think you may end up purchasing a used replacement mount,as it may be cheaper in the long run than shipping it back for repair.If you are so inclined to repair yourself,disassemble it taking images of each procedure so as to remember where everything goes and see if you can find the broken part. Contact Celestron to see if you can get the part and if so, good,if not, you should be able to locate a used mount on here or on Astro Mart. Sorry to hear about your misfortune.

Hard to tell what might be wrong without opening it up. It sounds likely that a gear tooth was broken or something similar, but it could also be that a drive gear was moved on its shaft and can simply be repositioned and the set screw retightened. If you're handy with tools, I'd suggest opening it up.

If anything is broken, you won't find too many parts available for replacement. Like Tim says, you're probably better off getting a used one. Then you can keep your old one for spare parts for the next time the scope gets blown over.

As others have already stated, it's impossible to say at this stage what may or may not be damaged.

However, you do say that the azimuth axis now rotates freely by hand, which, clearly before this misfortune, it was not designed to do.

This therefore might indicate that the motor (drive pinion) has become dislodged, (or disengaged) from the main, large, static (cog) wheel: hence the motor turns, as evidenced by the sound you hear when the HC is operated, but, without the engagement of the two sets of intermeshing teeth, does not rotate the azimuth axis.

I'm afraid you will have no alternative but to open up the azimuth axis drive if you wish to investigate this (any) possibility yourself, but perhaps, the attached archived text might help. (?)

As far as the OTA, it seems to have survived quite well. No visible damage, and an out of focus star was quite even and circular. Looked at the (filtered) sun today with it, and it performed quite well.

OK. Got it open. What I see is a small brass gear that is supposed to mesh with the large gear in the base of the mount. The small gear is rotating freely, and moving up an down easily on its shaft, with no visible means of securing it to the shaft. What next?

It's not likely that you can return the small gear to the original shape. As that gear meshes with the large gear in the repaired area you will see a tracking error. It could lead or lag depending on how you bent the teeth back into position. Damage to the large gear will show a problem only in one small region of azimuth. This you can probably ignore. There are many sources of small metric gears. It's likely that you can find a replacement. Try this source.

Not sure about the AZ gear as mine is a replacement AL unit. However, the gear meshes at the opposite end as the setscrew. As long as the large gear doesn't hit the screw, it can mesh anyplace along it's length. The small gear can also be reversed if that will help.

You should also note the AZ position of the damaged portion of the large gear and avoid using it in that region. Even though the small gear has been replaced, there will still be a tracking error in that region as the bent teeth will cause a lead or lag when engaged. It will be a small angle, a few degrees.

I think. I put the gear back on, with the set screw on the other side, where the hole was undamaged. Put the gear as far on the end of the shaft as I could, so the damaged tooth would be out of the way. It seems to be working, at least mechanically. Will have to wait until the next clear night to field test it.

Hey Doc, you should have the gear by now. I should tell you that Celestron uses some form of adhesive in addition to the set screw to retain it. I had to let the drive (out of the mount!) cook a few minutes on the stovetop* before I could remove it. Not sure I'd super glue it on though, think I'd rather have it slip than take a quater Moon out of the driven gear.

Had the scope out last night, and the mount performed normally. Conditions were not great, but the stars did not look right - could not get a pinpoint image on bright stars. Maybe the collimation is off. Will try a formal star test soon.